High-GI foods are foods that quickly get into your system - which results in your blood sugar rising quickly -
probably quicker than your insulin can counter it. As a rule we try to avoid eating too much High-GI foods, although when we have a
hypo we want some super High-GI food to
correct our low BGL quickly.

If you don't eat much sugary food, then you probably know the feeling of a sugar headache (similar to an ice-cream headache) as the sugar rush hits you. The idea with Low-GI foods
is to try and balance the sugar onset of the food you eat with the insulin you use.